[Haskell-cafe] Children elements with HXT

[Tony Morris]

Adding (a_remove_whitespace,v_1) as a parser option when running solves
it. Silly me.


Tony Morris wrote:
> I am trying to parse XML using HXT following
> http://www.haskell.org/haskellwiki/HXT/Conversion_of_Haskell_data_from/to_XML
>
> Here is my XML file (way.xml):
>
> <way id="27776903" visible="true" timestamp="2009-05-31T13:39:15Z"
> version="3" changeset="1368552" user="Matt" uid="70">
>   <tag k="access" v="private"/>
>   <tag k="highway" v="service"/>
> </way>
>
> The problem is when parsing, by reading the <tag> entries into the
> list held by the Way data structure, I cannot get anything but an
> empty list.
>
> Here is my parsing code:
>
> import Text.XML.HXT.Arrow
>
> newtype Way = Way {
>   tags :: [Tag]
> } deriving (Eq, Show)
>
> xpWay :: PU Way
> xpWay = xpElem "way" (xpWrap (Way, tags) (xpList xpTag))
>
> data Tag = Tag {
>   k :: String,
>   v :: String
> } deriving (Eq, Show)
>
> xpTag :: PU Tag
> xpTag = xpElem "tag" (xpWrap (uncurry Tag, k &&& v) (xpPair (xpAttr
> "k" xpText) (xpAttr "v" xpText)))
>
> When I run, I get the following result:
>
> Main> run = runX (xunpickleDocument xpWay [] "way.xml")
> [Way {tags = []}]
>
> Why is the tags list empty instead of holding two entries?
>
>
>   

-- 
Tony Morris
http://tmorris.net/